UV-waterborne polyurethane-acrylate nanocomposite coatings containing alumina and silica nanoparticles for wood: mechanical, optical, and thermal properties assessment

Abstract

The effect of alumina and silica nanoparticles on mechanical, optical, and thermal properties of UV-waterborne nanocomposite coatings was investigated. The addition of nanoalumina and nanosilica was shown to decrease the hardness because of nanoparticle aggregation. In comparison to the neat coating and despite the presence of aggregates, the scratch resistance of nanocomposite coatings was significantly improved. As expected, the gloss of UV-waterborne coatings was reduced following the addition of nanoparticles due to an increase of the surface roughness. Alumina and silica nanoparticles were found to enhance the glass transition temperature of PUA nanocomposite coatings by hindering the mobility of macromolecular chains at the interface around the nanoparticles. Finally, the interest and efficiency of grafting trialkoxysilanes was demonstrated with the study of nanosilica behavior. Not only was the dispersion of nanosilica enhanced following trialkoxysilanes grafting onto silica nanoparticles, but also the scratch resistance and the adhesion of UV-waterborne coatings containing nanosilica markedly increased even with 1 wt% content. Silica which is recommended in the wooden furniture and kitchen cabinet manufacturing industry as nano-reinforcement provides improved properties well suited in surface coating applications to efficiently protect surface of wood substrates.

Fumed silica as a filler for MUPF resin in the process of manufacturing water-resistant plywood

“…The presence of silica in lacquers and enamels enhances their thermal, optical and mechanical resistance, especially to abrasion and scratching. It also makes it possible to attain the desired gloss level of the coating (Royall and Donald 2002;Sow et al 2011). The use of nano-SiO 2 in the system with urea resin and wood preservative enhances fire resistance of wood as well as its dimensional stability and durability (Shi et al 2007).…”

Effect of Nanoalumina on the Electrochemical and Mechanical Properties of Waterborne Polyurethane Composite Coatings

“…Thus, addition of nanoalumina (hardness of 9 Mohs) particles inhibits the crack formation and propagation during the scratch process. It is also apparent that the addition of nanoalumina in higher concentrations decreases the hardness because of nanoparticle aggregation [34]. This may be the probable reason for relatively less resistance offered by the coating modified with 1.0% nanoalumina as compared to coating modified with 0.1% nanoalumina.…”

Improvement of adherence and anticorrosion properties of an epoxy-polyamide coating on steel by incorporation of an indole-3 butyric acid-modified nanomagnetite

“…The most commonly used nanoparticles are SiO 2 , TiO 2 , ZnO, Al 2 O 3 , Fe 2 O 3 , and clays. [1][2][3][4][5][6][7][8][9][10] For corrosion protection of metals, the addition of nanoparticles in organic coatings offers an acceptable environmental solution. The major documented benefit of the incorporation of nanoparticles in polymer coatings is reinforcement of barrier effect and improvement of mechanical properties.…”